But the more things change, the more they stay the same. Yes, links still matter a great deal for achieving rankings. But some other concepts that may seem outdated are reviving.

SEO cocitation was a hot topic many years ago as Google introduced anti-spam updates geared toward devaluing links from poor-quality blog networks. More recent discussions of cocitation have shifted the focus away from link juice and toward the words used around links.

These factors are all gaining traction in the Google algorithm as Google evolves and becomes smarter at detected manufactured links (versus earned links). For webmasters attempting to reshape an SEO strategy that failed in 2012 due to Penguin and Panda, re-engaging SEO cocitation is a smart move.

SEO Cocitation Core Concepts

1. Link juice flows backwards as well as forward

Most webmasters obsess on inbound links, working feverishly to earn them from reputable sources. Generally speaking, the more inbound root domain links acquired, the higher the domain authority, PageRank, rankings, and traffic.

But this orientation can lead to link juice hoarding. Often overlooked is the notion that outbound hyperlinks are also important in the link juice equation. Outbound links to high-authority sites are positive for the user-experience.

2. Good websites link to other good websites

Linking to other great websites in a competitive space is counter-intuitive as it may aid the enemy. This SEO cocitation concept is frustrating for new webmasters as it implies that top rankings are an exclusive club and breaking-in is impossible. There is some truth to this, but smart publishers need to understand that to get, they must also give.

Linking to high-quality, high-authority websites is also a positive signal to Google. The trick is to find high-quality sites that are relevant, but not competitive.

3. Linking to a bad neighborhood hurts a website

On the flip side, outbound links to a poor-quality domain suggests the website as a member of a bad neighborhood. This is particularly helpful to Google in their pursuit to de-value links from spammy blog networks that provide no value to end-users.

It is fairly easy for Google's algorithm to spot a cluster of low domain-authority sites that link exclusively to other low-domain authority sites. The manipulative intentions are even more obvious when the sites don't share any topical relevance to each other, are rarely shared in social media, and have poor time-on-site (i.e., are not useful).

4. The link graph uses the transitive property

The most advanced concept in SEO cocitation is the transitive relationship. Put in mathematical terms:

Website A Links To ---> Website C

Website A Links To ---> Website B

Website C’s authority is a benefit to Website B

Here, link juice flows backwards, and then forward. While there is no link between Website B and Website C, there is a transitive relationship based on the fact that Website A links to both of them. If Website C is highly authoritative, the transitive principle of SEO cocitation suggests that Website B will gain a benefit simply because Website A links to both.

5. The words around your links matter

More recently, the term cocitation has been expanded to include semantic analysis and word frequency – also called co-occurrence and semantic similarity. Specifically, several SEOs have found domains that are ranking on keywords that have never been used as anchors for inbound links.

There has always been evidence that the words on pages that link to a website (contextual phrases) are influential, but many SEOs see the importance of co-occurrence, or semantic similarity, increasing in the Google algorithm.

Conclusions

Trying to understand SEO cocitation can be difficult. But the basic takeaways for small business websites owners are clear:

Link freely to other highly authoritative websites in the space (i.e., relevant).

Don't link to bad neighborhoods.

When seeking inbound links, be mindful not only of the domain authority and relevance of the linking website, but where else that website links to. This will rule out most link buying tactics as those who sell links usually do so from networks, and almost always link to low-quality sites (i.e., other link buyers).

Webmasters should avoid being pulled into a bad neighborhood unknowingly by cocitation.

About the author

Adam Stetzer, Ph.D. is President and Co-Founder at HubShout, a leading SEO Reseller and SEM software and services provider. He holds a Doctorate in Industrial Psychology from Purdue University and has over 15 years experience in the Information Technology fields building enterprise software for Fortune 100 clients such as General Electric, Coca Cola, Pepsi, AT&T, Verizon, Nissan Motors and ChevronTexaco. He is a serial entrepreneur, but believes that owner passion and organic growth are the secrets to his start-up success. Dr Stetzer has been building software in the SEO space for the last 5 years. He lives and works in Rochester, NY.